Stories about the people, science and research of the Medical Research Council.

The history of animal research at the NIMR

by Guest Author on 4 December 2014

Staff with dogs at Rhodes Farm in 1928

Today’s research animals live in high-tech environments designed with welfare in mind. The contrast with the situation in the early 20th century when the MRC National Institute for Medical Researchwas founded is marked, and the institute itselfhas made a huge contribution to this progress. Here we look at just some of their contributions, extracted from a book telling the story of the research institute’s 100-year history.

No one does animal research for the sake of it, and those charged with looking after research animals are committed ― and held by law ― to ensuring that animals used in research are provided with the highest standards of care and welfare.

In the institute’s early days, animals were housed in individual labs, but in 1922 the MRC bought 39 acres of land at Mill Hill in north London to create field laboratories at Rhodes Farm. Within a year, there were specially designed facilities for breeding and keeping dogs and small animals, with local girls helping to care for and exercise the dogs. At the main institute site in Hampstead animals were kept in a new annex ― built in 1927 ― in “the highest possible standard of hygienic conditions for the keeping of experimental animals”.

But though animals were well cared for, they may not have always arrived at the institute in the best of health. Until the 1940s, NIMR, like other research laboratories, sourced many lab animals from the commercial pet trade, often inferior animals which couldn’t be sold as pets. As well as helping to raise standards of care and welfare and develop improvements in diet, housing and infection control, in 1947 NIMR helped the MRC to set up the Laboratory Animals Bureau to provide standard information on breeding, supplying, keeping and using lab animals. This was followed by an accreditation scheme for suppliers.

Working with the Institute of Animal Technology (IAT), NIMR was also instrumental in establishing animal technology as a recognised profession with professional training and education, setting standards for training to this day, including developing National Vocational Qualifications NVQs in animal technology, internal MRC CPD training programmes and a new Animal Technology Apprenticeship.

An all-in-one diet

Many laboratory animals are fed standard food pellets ― a diet containing all the nutrients they need ― not dissimilar to dry pet food. These pellets are now supplied by companies, but there was a time when research animals were fed with whatever food staff could get their hands on, including canteen leftovers.

This ‘wet mash’ soiled the cages and bedding, changing it daily was laborious, and post-war food shortages affected supplies. In 1949 two NIMR researchers released a diet called 41B, a complete rodent food, onto the market. These days, dry food is often supplemented with other food for variety and stimulation – the NIMR’s opossums, for example, dine on extra mealworms and fruit.

Mice with a modern-day ‘mouse house’

A house fit for a mouse

Animal cages have also undergone a revolution at NIMR. Starting out with wooden boxes that rodents developed a habit of gnawing through, designs evolved as metal became more available after the Second World War. The 1940s saw the first metal cages designed by NIMR staff, with water bottles (initially recycled ink bottles) and an area for food. These cages were easy to keep clean, and allowed staff to check on animals regularly with minimum fuss. Today small mammals live in transparent plastic cages.

Anyone who’s visited a mouse facility will be familiar with the red plastic shelters within cages in which mice nest. Because mice can’t distinguish between red and black, they feel safe and secure in the shelters, but technicians can still see them to check their health without disturbing them. It was work done at the NIMR by animal technicians and scientists which determined exactly the type of red that mice prefer.

On-demand sustenance

Automated feeding was introduced for rabbits in 1959 after their fondness for a new pelleted diet led to them becoming fat from over-eating. But there wasn’t enough time in the day for technicians to feed them little and often, so technology came to the rescue.

With the help of the engineering division, the Head of the Animal Division Doug Short adapted a system originally designed for the poultry industry to create a fully automated feeding and watering system. Food and water travelled in metal containers on a track around the outside of the cages, stopping at each cage. He also experimented with ‘self-cleaning’ cages, in which animal waste dropped into a central trough.

Rabbits using the automated feeding system in the 1950s (left) and an example of modern floor pen housing for rabbits

Barriers against bugs

Animals used in research must be free of disease-causing bugs, and all animal houses have policies to protect animals from bugs brought in from the outside. Today entering a mouse house requires overalls, shoe covers and hairnet, and some mouse houses, such as the MRC Mary Lyon Centre, require visitors to pass through an air shower. The 1920s equivalent at NIMR was a ‘bathing house’ where staff would wash and change into protective rubber clothing (like that in this photo of workers washing cages).

Workers wash animal cages in the 1920s

So, from pet trade cast-offs to specially bred animals, and from canteen leftovers to tailored food pellets, the NIMR has been at the forefront of progress in research animal care and welfare. We’ve come a long way from the days when animals were kept in the corner of the lab.